Target identification systems

• US 5,350,134 A
• Filed: 07/03/1973
• Issued: 09/27/1994
• Est. Priority Date: 07/03/1973
• Status: Expired due to Term

• Current Assignee: SELEX Sensors and Airborne Systems Ltd. (Leonardo S.p.A.)
• Original Assignee: Gec-Ferranti Defence Systems Limited (Leonardo S.p.A.)
• Inventors: Crawford, Ian D.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US06/374,791
• Time in Patent Office: 7,756 Days
• Field of Search: 244/3.16, 244/3.17, 244/3.11, 244/3.13
• US Class Current: 244/3.16
• CPC Class Codes: F41G 7/226 Semi-active homing systems, i.e. comprising a receiver and involving auxiliary illuminating means, e.g. using auxiliary guiding missiles
• CPC Class Codes: F41G 7/2293 using electromagnetic waves other than radio waves

Abstract

A target identification system includes a target marker for selecting, and directing radiation at, a target, a weapon delivery system, and means for establishing a two-way communication channel between the two by reflection from a selected target. The communication is by infra-red laser and coded information is sent between the target marker and the weapon delivery system to identify the selected target.

Claims

1. A target identification system which includes a target marker capable of selecting, and directing radiation at, a target, a weapon delivery system to which the target is to be identified, means for establishing between the target marker and the weapon delivery system a two-way communication channel over which pulsed radiation may be transmitted from one to the other by reflection from the selected target, and means carried by the target marker and the weapon delivery system for so encoding the radiation transmitted over the communication channel as to identify uniquely the selected target to the weapon delivery system.

2. A system as claimed in claim 1 in which the target marker includes a laser operable to transmit radiation towards the target and a radiation-sensitive detector operable to receive laser radiation reflected from the target.

3. A system as claimed in claim 2 in which the radiation-sensitive detector carried by the target marker is provided with an optical system having an optical axis parallel to that of the laser carried by the target marker.

4. A system as claimed in claim 1 in which the weapon delivery system includes a laser operable to transmit radiation towards the target and a radiation-sensitive detector operable to receive laser radiation reflected from the target.

5. A system as claimed in claim 4 in which the radiation-sensitive detector carried by the weapon delivery system is provided with an optical system having an optical axis parallel to that of the laser carried by the weapon delivery system.

6. A system as claimed in claim 5 in which the radiation-sensitive detector carried by the weapon delivery system is sensitive to the direction of incidence of radiation falling upon it.

7. A system as claimed in claim 4 in which the weapon delivery system includes means operable to prevent the transmission of radiation by its laser except when the optical axis of the laser is directed towards an apparent source of radiation.

8. A system as claimed in claim 1 in which the encoding means carried by the target marker includes means for causing the laser carried thereby to emit a train of pulses of radiation at a predetermined repetition rate until a pulse of radiation is received by its radiation-sensitive device.

9. A system as claimed in claim 8 in which the encoding means carried by the target marker also includes means responsive to a received pulse of radiation to transmit a single pulse of radiation after a preset delay.

10. A system as claimed in claim 1 in which the encoding means carried by the target marker includes means for determining the range of the target from the target marker.

11. A system as claimed in claim 1 in which the encoding means carried by the weapon delivery system includes means responsive to the detection of a train of pulses of radiation having a predetermined repetition rate to generate a train of gating pulses.

12. A system as claimed in claim 11 in which the encoding means carried by the weapon delivery system also includes means responsive to a required number of coincidences between gating pulses and detected pulses of radiation to cause the laser to emit a single pulse of radiation.

13. A system as claimed in claim 1 in which the encoding means carried by the weapon delivery system includes means for determining the range of the target from the weapon delivery system.

14. A system as claimed in claim 2 in which the laser is operable to emit pulses of intra-red radiation.

15. A system as claimed in claim 14 in which the laser is a Q-switched device.

16. A target marker for a target identification system as claimed in claim 1 which includes a laser operable to transmit radiation towards the target and a radiation-sensitive detector operable to receive laser radiation reflected from the target.

17. A target marker as claimed in claim 16 in which the encoding means includes means for causing the laser to emit a train of pulses of radiation at a predetermined repetition rate until a pulse of radiation is received by its radiation-sensitive detector.

18. A target market as claimed in claim 17 in which the encoding means also includes means responsive to a received pulse of radiation to transmit a single pulse of radiation after a preset time delay.

19. A target marker as claimed in claim 16 which includes means for determining the range of the target from the target marker.

20. A weapon delivery system for a target identification system as claimed in claim 1 which includes a laser operable to transmit radiation towards the target and a radiation-sensitive detector operable to receive laser radiation reflected from the target.

21. A weapon delivery system as claimed in claim 20 in which the radiation-sensitive detector is sensitive to the direction of incidence of radiation falling upon it.

22. A weapon delivery system as claimed in claim 21 in which the encoding means includes means responsive to the detection of a train of pulses of radiation having a predetermined repetition rate to generate a train of gating pulses.

23. A weapon delivery system as claimed in claim 22 in which the encoding means also includes means responsive to a required number of coincidences between gating pulses and detected pulses of radiation to cause the laser to emit a single pulse of radiation.

24. A weapon delivery system as claimed in claim 20 in which the encoding means includes means for determining the range of the target from the weapon delivery system.

25. A system as claimed in claim 4 in which the laser is operable to emit pulses of infra-red radiation.

26. A system as claimed in claim 25 in which the laser is a Q-switched device.